Fuel injector timing device



Oct. 5, 1943. F. ALWARD FUEL INJECTOR TIMING DEVICE Filed March 18, 1941 lNvENToR 74601019 Rwr'd BY mvn/ ATTORN EYS Patented Oct. 5, 1943 UNITED STATES PATENT OFFICE FUEL INJECTOR TIMING DEVICE Francis Alward, Lexington, Mass.

Application March 18, 1941, Serial No. 383,946

(CI. 20G-53) 2 Claims.

This invention relates to timing devices, and more particularly to timing devices adapted to be used in fuel injector systems, such as those in compression ignition motors, commonly referred to as Diesels An object of the invention is to provide a means whereby the actual injection of the iluid into Aeach cylinder may be timed so that the injectors may be set to inject fuel at the proper moment to secure proper functioning and the greatest efficiency of operation.

A further object is to provide a device of the character described, which is readily adaptable to existing injectors of various types and which will be economical in construction and simple and sure in operation.

While in the accompanying drawing I have shown my invention adapted to the Bosch,4 type of injector, it will be readily appreciated'that with slight modifications my invention may be adapted to any of the standard types of iuei'injectors.

In the accompanying drawing-v Fig. 1 is a sectional plan view' o! my invention adapted to a standard fuel injector;

Fig. 2 is a diagrammatic view oi' a circuit which may be used with my device; j

Fig. 3 shows a form of device for recording the injections in the various cylinders; and

Fig. 4 shows an additional form of device for recording the injection into the various cylinders.

In the accompanying drawing, III represents the conventional fuel injector having an injector pintle II mounted therein. lOil is normally pumped under pressure through the pipe I2 and the channel I3 into the chamber I4 of the injector against the chamfered end I5 of the pintle II. f

Mounted in the rear end I5 of the injector I0 is a spring I'I which engages the end/I8 of the pintle II. The spring is positioned within the end IB by means oi' the externally threaded head I9 provided with threads 20 which engage the threads 2l on the end I5.

In normal use the injector I0 is provided with a head having no opening therethrough and a cap member screws on to the head. When the fuel pumped through the tube I2 and the chan- .nel I3 builds up sufficient pressure in the chamber I4 against the chamfered end I5 of the pintle Il, the spring I1 will be forced back long enough to permit a small quantity of fuel to enter the combustion chamber of the engine. By

tightening or loosening the head I9 the tension of the spring Il can be increased or decreased.

Having generally described the operation of a type of injector, my invention consists inA applying to such an injector a timing device 25. The outer cap and the head I9 of the injector are removed and a similar head I9 having an opening is substituted therefor with an externally threaded cap 2l having an opening 28 in its top passing over the head I9.

A casing is provided for my timing device having a plate 3| at the top thereof fastened to the post 32 by the screw 33. The plate 3| may be readily removed to adjust, repair or replace parts of my timing device. Mounted in the cas ing 30 is a condenser 34 and a pair of contact points 35 and 36. The contact point 35 is rigidly mounted in the standard 3l on the screw 38 so that its position may be delicately adjusted with relation to the standard 3l. The contact point 35 is mounted on an arm 33 which is pivoted at 4I) to the casing 30. A spring 4I tends to keep the contact points 35 and 36 in engagement.

Mounted in the casing 30 is a rod 45 having a cammed end 45. A light spring 41 engages the pin or collar 48 on the rod to normally hold it toward the injector, and the end 49 extends through the cap 2l and the head IS of the injector to make contact with the end I8 of the pintle II.

The arm 39 is provided with a cammed face 50 which is adapted to engage the cammed end of the rod 45. Running from the standard 3l is a wire 5I from which wire 52 runs to the condenser. The wire 5I engages the terminal 53 in the end 54 of the timing device. A wire 55 runs from the terminal 53 to the terminal 56 of the induction coil 51 and a wire 58 is run from the battery to the terminal 58 of the induction coil 51.

A wire 50 leading from the terminal 6I runs to any suitable recording device. This may be a spark plug 52 adapted to score paper or metal ribbon 53 mounted on a disk 64. The disk 64 is mounted for rotation on an axle which may be attached to the crankshaft or any other convenient takeoff which will rotate it at motor speed. The tape may be lined with degree marks 5l to indicate its position.

When the oil builds up in the chamber I4 to the injection point and the pintle ii is forced rearwardly, the end 4B of the rod 45 engaging the cam face 50 on the arm 39 will momentarily break the contact points 35 and 36. This will allow the current produced in the coil 51 to flow to the plug B2 and to jump the gap to the disk 64 and burn or pit the paper ribbon 63. These marks or pits, as indicated at 68, will extend in length where the injection system is of the variable type so that after the disk 64 has been stopped a record of the timing range in degrees,.

before and after top dead center, will be indicated on the paper ribbon as well as the initial period of injection. If the injection system 4is `not of the ,variable type, the marks or pits will be' made in the vsame place on each revolution.

It will be seen that with the use of my device it is possible to accurately check and record the timing'period if the ignition systemis of the fixed type, and the timing range if the system is of It will also be appreciated thatbther means may be used to make and break the contact and that the specific form and arrangement shown the variable type, when the engine is running at any and all speeds from cranking to full throttle.l

It will be further appreciated that with my dey vice the recid will be made at the point of actual moment of fuel injection so that an eXtremely accurate timing check may be made.

A It will be understood of course that the entire device. is grounded due to the insertion of the injector into the motor block 69. If desired, a

timing light or stroboscope 'Hl may be used against timing marks 1I on the iiywheel 12 or on a revolving disk attached to the shaft and re-V volved at engine speed.

It will bel appreciated that while I have shown my device operating with a specic form of fuel injector, by a slight modification in the connecting means it may be adapted to any type of fuel injector which has an operating member such as the pintle I I.

'operable bysaid member operating upon said movable contact to move said contact into circuit opening position upon unseating movement of the valve spindle.

2. The combination with a fuel injector nozzle of the fluid pressure type employing a reciprocatory valve mounted in the injector casing and unseating to discharge fuel pressure, said casing having a threaded extension on the end of the .casing opposite the nozzle, of a. switch device comprisinga housing removably coupled with the threaded extension of the casing, said housing enclosing a switch mechanism and means to operate the switch comprising a rod, said rod extending into contact with the reciprocatory valve and means to cause the rod to follow the motion of the valve. Y FRANCIS ALWARD. 

